U.S. Pat. Nos. 3,718,908 and 4,020,463 are both directed to storage, retrieval and presentation of a signature image at the point of execution of a transaction in order to assist the clerk or teller in accurately verifying the identity of the other party to the transaction. Recognizing the transitory nature of display signature presentations and the existance of a printer at many terminal stations, improved all points addressable matrix printers have been suggested for use in displaying graphic images such as signatures. Capitalizing on modern technology, these printers usually are controlled by a microprocessor which generates each character from one or more read only memory chips containing the seven or eight wire bit patterns, also called slices, necessary to generate each character of one or more character fonts. By receiving each print wire control bit directly from a host computer or mass storage rather than referring to a read only memory character generator, these printers can print virtually any image within the constraint of the paper carriage without other limits as to shape or size of the images.
Although these matrix printers may be controlled by a microprocessor, and therefore be very flexible, the mechanics of a matrix printer is oriented to printing rows of characters in sequence like a typewriter. Accordingly, it is important to provide the image information to the print control logic or microprocessor in such sequence and format so as to permit full speed operation of the mechanical printer hardware to avoid unduly delaying the financial transaction being executed. Further, image information is often collected and stored as a plurality of sequential horizontal scans of video data. Matrix printers in contrast accept vertical columns of 7 or 8 picture elements, 5 to 8 columns being combined to create each character as the print head moves along the line of characters being printed.